This circuit was obtained from an Electronics Design of 1964. The circuit makes use of tunnel diodes that are uncommon today. The circuit works with very weak signals.
In the figure we have the simple way to obtain a digital inverter using a general-purpose...
This circuit works with only 1.5 V and can be powered by a solar panel. The circuit is from 1991....
This circuit was found in a 1969 EEE. The circuit uses transistors from the era that can be...